A see-through adaptive phoropter provides the ability to automatically measure a patient's refractive prescription while allowing the patient to view targets at both near and far distances. The system automatically measures the patient's refractive error and compensates for it to bring a distant eye chart into focus. Current adaptive phoropter systems use reflective deformable mirrors to compensate for aberrations in the eye. The concept of the Shack Hartmann sensor coupled with adaptive optics originated in the 1990's through research performed at the University of Rochester. These systems were rather large and applied reflective rather than refractive optics. When reflective deformable optics are used, it is difficult to configure the phoropter so that it is compact and mobile. It is therefore desirable to provide phoropters with better characteristics.